Modulating action of microbiota of carriers of Down's syndrome on cariogenic microbiota

Abstract

Carriers of Down Syndrome have low prevalence of tooth decay, despite the fact that they show precarious oral hygiene. This research was carried out with the intent of evaluating the possible action of strains that produce bacteriocins as regulators of the carrier of Down Syndrome cariogenic microbiota. Streptococcus mutans and Streptococcus sobrinus are the main acid producers in the oral cavity.Consequently, they were tested antagonistically with strains isolated from the individuals with Down Syndrome in order to verify if cariogenic bacteria were being inhibited by the by the carrier's strains. Streptococcus mutans and Streptococcus sobrinus were isolated with the utilization of agar saccharose bacitracin medium and identified through standard biochemical tests. Samples of carriers'supragingival plaques were collected, spread through dissemination in Agar Mitis Salivarius and after isolation were cultivated in BHI liquid medium.10 cultures from syndromics were seeded in the Muller Hinton medium. After the growth, the colonies in the Petri dishes were treated by chloroform. Then, one portion of the cariogenic bacterium cultures was mixed with soft brain-heart infusion medium and immediately transferred to the Petri dish with the test cultures. Two of the ten tested strains presented a zone of inhibition against Streptococcus mutans. The discovery of strains that produce antibacterial substances may be responsible for the low prevalence of tooth decay in individuals with Down Syndrome. These findings may help to understand the relationship between oral microbiota and pathological tooth decay.